From 3cfd56fcf68ee795b9386c2f23ef83ff532ba897 Mon Sep 17 00:00:00 2001
From: "Thomas G. Lockhart" <lockhart@fourpalms.org>
Date: Sun, 15 Aug 1999 06:46:49 +0000
Subject: [PATCH] Repair the check for redundant UNIQUE and PRIMARY KEY
 indices. Also, improve it so that it checks for multi-column constraints.
 Thanks to Mark Dalphin <mdalphin@amgen.com> for reporting the problem.

---
 src/backend/parser/analyze.c | 46 ++++++++++++++++++++++++++----------
 1 file changed, 33 insertions(+), 13 deletions(-)

diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index d4a1ef57ef..e3c9feb677 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -5,7 +5,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- *	$Id: analyze.c,v 1.116 1999/07/19 00:26:18 tgl Exp $
+ *	$Id: analyze.c,v 1.117 1999/08/15 06:46:49 thomas Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -579,6 +579,9 @@ transformCreateStmt(ParseState *pstate, CreateStmt *stmt)
 	columns = NIL;
 	dlist = NIL;
 
+	/*
+	 * Run through each primary element in the table creation clause
+	 */
 	while (elements != NIL)
 	{
 		element = lfirst(elements);
@@ -588,6 +591,7 @@ transformCreateStmt(ParseState *pstate, CreateStmt *stmt)
 				column = (ColumnDef *) element;
 				columns = lappend(columns, column);
 
+				/* Special case SERIAL type? */
 				if (column->is_sequence)
 				{
 					char	   *sname;
@@ -625,6 +629,7 @@ transformCreateStmt(ParseState *pstate, CreateStmt *stmt)
 					blist = lcons(sequence, NIL);
 				}
 
+				/* Check for column constraints, if any... */
 				if (column->constraints != NIL)
 				{
 					clist = column->constraints;
@@ -815,28 +820,43 @@ transformCreateStmt(ParseState *pstate, CreateStmt *stmt)
  * or if a SERIAL column was defined along with a table PRIMARY KEY constraint.
  * - thomas 1999-05-11
  */
-	if ((pkey != NULL) && (length(lfirst(pkey->indexParams)) == 1))
+	if (pkey != NULL)
 	{
 		dlist = ilist;
 		ilist = NIL;
 		while (dlist != NIL)
 		{
-			int			keep = TRUE;
+			List *pcols, *icols;
+			int plen, ilen;
+			int	keep = TRUE;
 
 			index = lfirst(dlist);
+			pcols = pkey->indexParams;
+			icols = index->indexParams;
 
-			/*
-			 * has a single column argument, so might be a conflicting
-			 * index...
-			 */
-			if ((index != pkey)
-				&& (length(index->indexParams) == 1))
+			plen = length(pcols);
+			ilen = length(icols);
+
+			/* Not the same as the primary key? Then we should look... */
+			if ((index != pkey) && (ilen == plen))
 			{
-				char	   *pname = ((IndexElem *) lfirst(index->indexParams))->name;
-				char	   *iname = ((IndexElem *) lfirst(index->indexParams))->name;
+				keep = FALSE;
+				while ((pcols != NIL) && (icols != NIL))
+				{
+					IndexElem *pcol = lfirst(pcols);
+					IndexElem *icol = lfirst(icols);
+					char *pname = pcol->name;
+					char *iname = icol->name;
 
-				/* same names? then don't keep... */
-				keep = (strcmp(iname, pname) != 0);
+					/* different names? then no match... */
+					if (strcmp(iname, pname) != 0)
+					{
+						keep = TRUE;
+						break;
+					}
+					pcols = lnext(pcols);
+					icols = lnext(icols);
+				}
 			}
 
 			if (keep)